Coal-to-natural gas process selection!
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A beginner here is asking: for the coal-to-natural gas projects that are currently underway or about to start in our country, which process is being used – direct hydrogenation (2CO+2H2=CH4+CO2) or the traditional process with a H2/CO ratio of 3:1? Thank you. :) This post was last edited by Zhenzhen Youci on 2009-4-9 00:14 ]
It must be under conditions where the H2/CO ratio is around 3; the former reaction is a reversible process of methane and carbon dioxide reforming, and it is difficult to occur. Incidentally, the main methanation processes currently in use are the Davy process and the Topsoe process, and it is likely that only domestic companies can purchase these technologies. This post was last edited by firefox1981 on 2009-4-10 16:29.]
It’s a pity that neither of them has yet achieved any results.
I think a 3:1 ratio is better. This area is relatively well-developed in the domestic market. No problem. This post was last edited by firefox1981 on 2009-4-10 16:29.]
Coal-to-natural gas is another large-scale coal chemical development project launched in China, following coal-to-oil and coal-to-olefins. With the upcoming increase in natural gas prices in the country, coal-to-natural gas appears to be a good opportunity. Currently, domestic companies such as Datang, Huaneng, and Shenhua have all gotten involved in this project, with Datang being the fastest in terms of progress. However, the only foreign commercial project for coal-to-natural gas is that of U.S.-based Megapower Energy, and it has been operating at a loss; it has only started to turn a profit in recent years due to rising oil prices. The carbon dioxide produced as a by-product is sold to oil companies in Canada for use in oil replacement processes. Therefore, there are no issues with the technology for large-scale production of coal-to-natural gas; the “blue gas technology” is primarily used, and the three main reactions involved are as follows: 1. Steam reforming: C + H2O(g) → CO + H2, endothermic reaction with -131.4 kJ/mol of energy absorbed. 2. Water-gas shift reaction: CO + H2O(g) → CO2 + H2, exothermic reaction releasing 41.2 kJ/mol of energy. 3. Methanation reaction: C + 2H2 → CH4, exothermic reaction releasing 74.7 kJ/mol of energy. The overall reaction is: 2C + 2H2O(g) → CO2 + CH4, endothermic reaction with -15.5 kJ/mol of energy absorbed. This post was last edited by firefox1981 on 2009-4-24 at 11:30
This post was last edited by Zhenzhen Youci on 2009-5-4 at 16:29. Coal-to-natural gas is another large-scale coal chemical development project launched in China, following coal-to-oil and coal-to-olefins. With the upcoming increase in natural gas prices in the country, coal-to-natural gas appears to be a good opportunity. Currently, domestic companies such as Datang, Huaneng, and Shenhua have all gotten involved in this project, with Datang being the fastest in terms of progress. However, the only foreign commercial project for coal-to-natural gas is that of U.S.-based Megapower Energy, and it has been operating at a loss; it has only started to turn a profit in recent years due to rising oil prices. The carbon dioxide produced as a by-product is sold to oil companies in Canada for use in oil replacement processes. Therefore, there are no issues with the technology for large-scale production of coal-to-natural gas; the “blue gas technology” is primarily used, and it involves three main reactions: 1. Steam reforming: C + H2O(g) → CO + H2, endothermic reaction with -131.4 kJ/mol of energy absorbed; 2. Water-gas shift reaction: CO + H2O(g) → CO2 + H2, exothermic reaction releasing 41.2 kJ/mol of energy; 3. Methanation reaction: C + 2H2 → CH4, exothermic reaction releasing 74.7 kJ/mol of energy. The overall reaction is: 2C + 2H2O(g) → CO2 + CH4, with an endothermic value of -15.5 kJ/mol. – Note: This post was copied from the Haichuan Chemical Industry Forum; the address of this post is: http://bbs.hcbbs.com/viewthread.php?tid=438294. Personal opinion: The overall reaction actually does not hold true, as the three reactions do not take place in the same reactor, and their respective heat balances differ; simply adding them together has little meaning. This is the more mature two-step method. Currently, some companies at home and abroad are working on one-step synthesis of natural gas, primarily through catalytic gasification, but it is still in the research stage.